Unit heater and air conditioner



C. A. DUNHAM ETAL UNIT HEATER AND AIR CNDITIONER Nov. 18, l1941'.

original Filed Feb. 4, 1958 Y face.

Patented Nov. 18, 194i l 2,263,074; UNH` HEATER Aimant coNnrrroNEn Clayton A. Dunham, "Glencoe, and David N.

'(lrosthwait, Jrf, Chicago, Ill., assignors to C. A. Dunham Company, Marshalltown, Iowa, a corporationot Iowa Original application February j4, 1938, Serial No, 188,598. Divided and this application February 23, 1940, Serial No. 320,410

's claims." 1 'This invention relates to certain new and use-1- ful improvements in an air-conditioner unit adapted to be positioned similarly to 'an ordinary radiator within a room, and designed to either heator cool the airwithina room.

(ci. csr-'43)' flowing air,

This. unit is designed to form part of a 'suit- 'unit with the heat-transfer fluid medium, for

able heatingor 'cooling system which'supplies the example steam in winter and cold waterl in summer. It is well known that, ,on the average,

about three times as much heat transfer surface is required to adequately cool the air when'the cooling ,medium used is within the range of to 50 Fahrenheit, as is required to heat the same space with' steam in the temperate zone. A suitable radiator or heat-transfer device is provided l which automatically provides.'for this change in The principal object of this'invention is'topr'o- 'loy fopenings 55') serves to equalize the distribution between the several tubes 49. It will be noted.-

, heat-transfer surface as the temperature requirements vary. v 2.0

vide an improved radiator or heat-exchange unit, .Y

the effective lcapacity of which is suitably 'and automatically varied' in accordance with the use of heating or cooling medium therein.

Other objects and advantages of this invention will be more apparent from the following detailed'description of certain approved forms of mechanisms constructed and-operating accord,`

'ing to the principles of this invention,

This application-is a division of copending ap? plication Serial No. 188,598, 'filed February 4:, 1938 (now United States LettersA Patent No.

described and illustrated.;

In the accompanying drawing: ',Fig. 1 is an enlarged vertical section th-roug the radiator or heatexchanger, with the greater portion of the center vof the assembly broken Fig. 2 isI a .horizontal section throughone end portion of this heat exchanger, the' view beingl taken substantially on the line I4.-| 4 of Fig. 1;v

substantially horizontal tiers of vfive tubes each, the tubes of each successive tier being staggered While the number and arrangement of Wthese tubes 49 could beevaried, inthe example here shown these tubes are arranged in three lpositionedr vertically.

introduced into, one end of the tubes ofthe upper tier, and thence flows alternately back and forth through the Vsuccessive tiers. .'For this reason the successive tiersare inclined slightly from the j horizontal to facilitatedrainage.

The fluid heating or cooling medium is introduced into the header 54 into `which is connectedV vone end of each'of the'upper tiers of tubesv49.

An internal web 55 (which may' be provided with that in the example here shown the tubesf49 are of ovalvcross-section withthegreatest diameter At ,opposite `ends of the upper and nextlower' tiers of tubes 49 are con. nected by the h 'eader 56 divided by an-internal lweb 51 having a port 58 adapted to'be closed by a movable valve member 59carri'ed by the ther- .mostat'ic'di'sk 80.` This functions the same as the usual thermostat'ic trap so that when steam is used' as a heating-medium and the chamber 6I becomes filled withsteam disk S0 will expand and'cause valve member 59 to close the port 5 8.

- In this manner, whensteam is used'as a heating medium the steam' is confined to the uppermost tier'of, tubes.49. As condensate accumulates in chamber 8l, the trap releases it and permits the condensate to drain out through port 58.

The intermediate and lower tiers of 4'tubes are y [connected-at the opposite end by the -neader 82 2,205,716) in which the` entire unit is more fullyl (it will be noted that there is no connection beheating medium' only thefupper tier o1 tubes is filled with steam, but the condensate must drain through the'two lower tiers on its way to the "drain pipe 64, and thus these lower tiers will act as an economizerl to extract the maximum quantity of heat from the hot water.

Although separatel fins on .each pipe, or each tier of pipes, couldV obviously be used, it will be y noted that-as here shown continuous ilns are maximum surface contact with the upwardly.

mounted on boththe upper and intermediate tier's`of pipes. In this manner the flnsof the intermediate tier .serve as additional radiating surface for the upper steam-filledpipe's. 'I'hese ns 50 are intermediately crimped or bowed asindicated at in Fig. 1 thereby permlttingthe two series of pipes 49to be. inclined somewhat withfrelation to one another for drainage pur- The'heating or `cooling 4medium is.

heat-exchange.;` the)vv poses. The intermediatebowed portions 65 of Y' the ns also serve to impede the progress ofthe upwardly flowing air and thus provide for greater heat-transfer. The second series of fins l are A exchange surface is necessary during the cooling season since the temperature of the cooling medium does not differ as greatly from the prevailing air temperature as does steam during the heating season.

Itwill be noted that the heating or cooling medium and the air ow in opposite directions, that is the upwardly owing air stream, encounters the lower cooler pipes (during the heating nate ends so as to. connect the tiers in series, an inlet tting at one end of the uppermost tier, an

outlet fitting at the other end of the lowermost tier, said tiers slanting downwardly to provide -gravity drainagefrom. the inlet to the outlet,

a thermostatic trap in the header connecting the upper and next lower tiersl so that steam willbe conned to the upper tier but condensate or cooling fluid can ow continuously through the series of tiers, and continuous radiating fins mounted on both the upper and next lower tiers of conduits so that extended radiating surface will be provided for the steam heated tie1'.

4. A heat-exchange apparatus for an air-conditioner unit, said apparatus comprising a plurality of tiers ofsubstantially parallel conduit sections, headers connecting the' tiers at alternate ends so as to connect the tiers in series,

- an inlet fitting at one end of the uppermost tier,

season) and encounters the upper-hotter pipes v after 'the air has been somewhat preheated.

-This is the most effective system for heatexchange. temperatures, during the cooling season.

1. A heat-exchange for an air-conditioner unit,

, said apparatus comprising a plurality of conduit sections connected in series and adapted to contain either a hot or cold fluid medium, a supply The same is true, with a reversal of inlet at one end of the series'and an outlet connection at the other end of the series, said sections being 4doiivrlwardly inclined from inlet tooutlet to provide uninterrupted gravity drainage and a thermostatic trap positionedfb'etween two of the sections forming a short steam section y `from the inlet to the trap and a longer condensate section from the trap to the outlet, said trap adapted, when steam is used for heating purposes, to prevent the passage of steam into the sections beyond the trap, the trap openingwhen condensate accumulates in front of the trap to permit the condensate to flow through the following sections whereby additional heat is transferred from the hot water, the trap remaining open when a cooling medium is used to provide a maximum heat transfer area necessary to effect a cooling of the air and being at least twice that of the steamheating transfer area.

2. A heat-exchange apparatus for an air-conditioner unit adapted to automatically provide necessary increased heat transfer area when used for cooling, said apparatus comprising a plurality of tiers of substantially parallel conduit sections of substantially equal size, headers connecting the tiers at alternate ends so as to connect the tiers in series, an inlet fitting at one to receive either hot'or cold fluid medium, a i

end of the uppermost tier, an outlet tting at the other end of the lowermost tier, and a thermo` static trap in the header connecting the upper and next lower tiers so that steam will be coniined to the upper tier but condensate or cooling fluid can flow continuously into the series of tiers below the trap, said tiers being downwardly iriclined and without obstruction whereby all such fluid is .continuously drained from the apparatus.

l 3. A heat-exchange apparatus for an air-conditioner unit, said apparatus comprising a plurality of tiers of substantially parallel conduit sections, headers connecting the tiers at alteran outlet fitting at the other end of the lowermosttier, anda steam sensitive thermostatic trap in the header connecting the upper and -next lower tiers and vdividing th'e series of tiers in the two tiers for continuous and complete drainage purposesr 5. A heat-exchange apparatus for an air-conditioner unit, said apparatus comprising an elongated conduit through which either hot or cold fluid medium is to be circulated and having a common outlet for both mediums, and a thermostatic trap interposed at a point intermediate the ends/of the conduit to divide the conduit into two sections the first a relatively shortl steam sectiony and the second a longer condensate section, the trap conning steam to only the first `of these sections when steam is used as a heating medium, but the trap opening when exposed,-

to liquid so that both sections will be lled by a heat-exchanging liquid, said yconduit being inclined downwardly without obstruction from be `low thev trapto the outlet whereby the liquid passing the trap will be continuously from the conduit.

6. A heat exchange apparatus for use in `an drained air conditioner unit comprising. a plurality of v conduit sections connected in series and adapted supply inlet at one end of the series and an outlet at the other end, said sections sloping downwardly to provide a continuous drain for the heating or cooling medium, and a thermostatic trap positioned between` the inlet end and the' outlet end to divide the series of sections into a short heating portion from the inlet to the` trap and a longer portion from the trap to the outlet in about the ratio of oneto two, said trap adapted to automatically closeA in the presence of steam' to utilize only the shorter portion for steam heating but adapted to automatically remain open when a cooling medium is used to provide a cooling area of about three times that of the heating area.-

' 'CLAYTON A. DUNHAM.

DAVID N. CROSTHWAIT, JR. 

